Conventionally known is a spinning forming device designed to transform a plate by pressing a processing tool against the plate while rotating the plate. The spinning forming device normally includes a mandrel (shaping die) attached to a rotating shaft and performs forming in such a manner that the plate is pressed against the mandrel by the processing tool.
In recent years, proposed is a spinning forming device designed to perform spinning forming while locally heating the plate. For example, as a spinning forming device for a titanium alloy, PTL 1 discloses a spinning forming device configured such that a portion (transform target portion) of the plate which is pressed against the mandrel by a spatula (processing tool) is heated by high frequency induction heating.
As a heater suitable for the spinning forming device, the inventors of the present invention have developed a heater including a coil portion extending in a rotational direction of the plate and having a doubled circular-arc shape facing the plate (see PTL 2). By using such a heater, local heating of the transform target portion of the plate can be continuously performed in the rotational direction of the plate. Thus, excellent forming can be realized.